Meta Coding Question: Indent Root-to-Leaf Paths by Column

You are asked to produce a printed representation for every root-to-leaf path in a binary tree where each node is indented according to its column on that path. Columns are assigned with root = 0, left child = c - 1, right child = c + 1. For each individual path, you compute the minimum column value m encountered on that path, shift all columns by -m so the minimum becomes 0, and then indent each node with one leading space per shifted column. Output each path as a multi-line string with top-down node order (root first, leaf last).

How the interview typically flows:

• Clarify input/output and node definition, confirm that each path is treated independently (per-path column shift).
• Propose a traversal: DFS that tracks the current column and accumulates nodes and their columns along the current path.
• After reaching a leaf, compute the per-path minimum column, shift columns, build the multi-line string, and append it to the result list.
• Discuss complexity, edge cases (single-node tree, skewed trees, null root) and possible iterative alternatives.

Skills you should demonstrate:

• Correct DFS/backtracking to collect root-to-leaf paths and per-node column values.
• Ability to compute and apply a per-path shift, then format multi-line strings with precise indentation.
• Time and space complexity reasoning (O(n) time visiting nodes once; O(h) stack + O(n) output space, where h is tree height).

Hints: track a list of (node_val, column) along the path, compute min once you reach a leaf, then map to strings using ' ' * shifted_column + str(val). Be ready to discuss iterative DFS and memory trade-offs.